<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>燕云长风</title>
    <style>
      body {
        height: 5000px;
      }
    </style>
  </head>
  <body>
    宽&nbsp;&nbsp;&nbsp;：<input type="text" id="width" /><br />
    高&nbsp;&nbsp;&nbsp;：<input type="text" id="height" /><br />
    面积：<input type="text" id="height" /><br />
    <div>我是DIV</div>
    <button id="btn">点击次数</button><output id="calc"></output>
  </body>
</html>
